This invention relates to apparatus for stripping high-purity metal from cathode sheets on the opposite faces of which the metal has been deposited in sheet form by electrometallurgical processes such as electrorefining and electrowinning.
With a view to curtailment of human labor and increase in production, a variety of apparatus have been suggested and used for stripping high-purity metal layers deposited on the faces of a set of cathode sheets in an electrolytic cell. Typical of such known apparatus is the one utilizing a conveyor for receiving a set of cathode sheets as the same is hoisted out of a cell after the electrodeposition of desired metal thereon and for transporting the cathode sheet set to a stripping mechanism. After the metal layers have been removed, the cathode sheet set is reloaded on the conveyor, transported back to the electrolytic cell, and again placed therein by the hoisting mechanism.
The prior art apparatus thus requires a highly involved procedure of operational steps, necessitating the elapse of an undue length of time from the withdrawal of the used cathode sheets from the electrolytic cell to the replacement of the reconditioned sheets into the cell. As an additional problem, the stripping mechanism itself of the prior art apparatus is capable of handling only one or two cathode sheets at one time.
A typical known stripping mechanism is shown and described in Japanese Patent Application Laying-Open No. 49-79327 (79327/1974). In this stripping mechanism, a single cathode sheet with electrodeposited metal layers on the opposite faces thereof is suspended vertically, and a pair of parallel horizontal stripper rods are moved horizontally relative to the sheet in a manner such that an upper part of the sheet without the metal layers deposited is pinched between the rods. Thereafter, the sheet is lifted relative to the stripper rods so that the rods first engage the upper edges of the metal layers and then peel the layers off the sheet as the sheet is moved upward.
It is apparent that this mechanism cannot be said to be efficient because the two steps of relative movement between the stripper rods and the cathode sheet in different directions are necessary and because the stripping operation must be carried out sheet by sheet.